Volume data arguments must all be the same size. Volume data arguments must be 3-D arrays. Volume data arguments must be size 2x2x2 or greater. Volume data arguments must be all empty or all non-empty. The size of the x-coordinate argument must match the size or the number of columns of the volume data arguments. The size of the y-coordinate argument must match the size or the number of rows of the volume data arguments. The size of the z-coordinate argument must match the size or the number of pages of the volume data arguments.